JPS6154457A - Measuring device for speed of solid in multiphase flow - Google Patents

Abstract

PURPOSE:To improve the precision of a measurement of the speed of particulate coal, etc., in a solid-vapor or solid-liquid multiphase flow by transducing a friction sound, generated by a contacting plate installed between two points in the flow, into an electric signal. CONSTITUTION:Through holes 11 and 21 are bored in the piping wall of a flow passage 1 at an upstream and a downstream side at some distance in the flow direction of fluid. Contact plates 12 and 22 are fitted in the through holes 11 and 21 and have friction against the multiphase flow in the flow passage 1 to generate a friction sound. The friction sound is detected by piezoelectric elements 13 and 23 and transduced into electric signals, which are amplified by voltage amplifiers 14 and 24 and sent out to a signal processor 30. The speed of solid bodies in the flow passage 1 are calculated from the correlation of outputs of both voltage amplifiers 14, 24 with delay time.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、微粉炭焚ボイラ、００Ｍ焚ボイラ、ＣＷＭ
焚ボイラの混相流中の固体流速測定に関する。[Detailed description of the invention] [Field of industrial application] This invention is applicable to pulverized coal-fired boilers, 00M-fired boilers, CWM
Concerning solid flow velocity measurement in multiphase flow of fired boilers.

〔従来の技術〕[Conventional technology]

従来固気および固液二相流における固体の流速測定は次
の方法が試みられている。Conventionally, the following methods have been tried to measure the flow velocity of solids in solid-gas and solid-liquid two-phase flows.

（１）写真による流跡法 （２）静電気探針の相関法 （３）　　レーデ流速計法 （４）静電容量相関法 （５）光相関法 これらのうち、（１）の写真にょる流跡法は、固体の粒
子が１〜２顛と大きいものの輸送に用いられておシ、輸
送管の一部をアクリルまたはガラスなど可視できるテス
ト断面を設け、一定時間の粒子の流跡を写真撮影して、
流跡の長ブから固体速度を求めている。(1) Photographic trajectory method (2) Electrostatic probe correlation method (3) Rede current meter method (4) Capacitance correlation method (5) Optical correlation method Among these, the flow shown in the photograph in (1) The trace method is used to transport large solid particles, one or two times. A visible test section is set up in a part of the transport pipe using acrylic or glass material, and the trajectory of the particles is photographed over a certain period of time. do,
The solid velocity is determined from the length of the trajectory.

また、（２）の静電気探針の相関法は、混和流中にＡ、
Ｂ２個の静電気探針をある間隔おいて設置し、探針Ａと
探針Ｂとに固体が衝突したときの静電気を信号として検
出し、Ａ　１．Ｂの信号の相関を求め、この相関値から
固体速度を求めるものである。In addition, in the correlation method of the electrostatic probe (2), A,
B Two electrostatic probes are installed at a certain interval, and the static electricity when a solid collides with probe A and probe B is detected as a signal.A1. The correlation between the B signals is determined, and the solid velocity is determined from this correlation value.

（３）のレーザ流速計法は、固体にレーデを照射して流
速を測定するものである。The laser current meter method (3) measures the flow velocity by irradiating a solid with a radar.

（４）の静電容量相関法は、混相流中の配管上人。The capacitance correlation method (4) is a piping expert in multiphase flow.

Ｂ２点に対向電極をある間隔に設置してＡ点およびＢ点
を流れる流体の濃度に比例した静電容量を検出し、Ａ、
Ｂ２点の相関を求めるものでるる。A counter electrode is installed at a certain interval at point B2, and the capacitance proportional to the concentration of the fluid flowing through points A and B is detected.
There is something to find the correlation between the B2 points.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

しかし、（１）の写真による流跡法の場合には、測定に
時間がかかる大きな欠点があフ、また、管の半径方向の
局所的な流速は測定不能である。However, in the case of the photographic trajectory method (1), the major disadvantage is that measurement takes time, and local flow velocity in the radial direction of the pipe cannot be measured.

また、粒子が数ミクロンと小さな固体については測定で
きないことや、可視部が必要なため、よごれる個所では
使用できない欠点もある。Another disadvantage is that it cannot measure solid particles with particles as small as a few microns, and because it requires a visible part, it cannot be used in dirty areas.

また、（２ンの静電気探針の相関法は、探針Ａに衝突し
た粒子が必ず探針ＢＫ衝突する必要があシ、固体濃度が
増すと、探針Ａと探針Ｂとの信号相関がとれなくなった
シ、また、固体の静電気は電圧が不揃であるため、測定
誤差が大きな欠点がある。In addition, the electrostatic probe correlation method (No. 2) requires that particles that collide with probe A always collide with probe B, and as the solid concentration increases, the signal correlation between probe A and probe B increases. Moreover, since the voltage of static electricity in a solid is uneven, there is a drawback that there is a large measurement error.

さらに、（３）のレーザ流速計法は、前記のように、固
体の粒径が不揃いの場合、それぞれの気体速度と固体速
度の差があるので、穏々の固体速度に比例した速度情報
（周波数）が混在して検出され、測定誤差が増すこと、
固体濃度が増すとレーザ光の散乱による減衰のため、速
度情報の検出ができなくなるなどの欠点がある。Furthermore, in the laser anemometer method (3), as mentioned above, when the particle size of the solid is uneven, there is a difference between the respective gas velocities and solid velocities, so velocity information proportional to the moderate solid velocities ( frequency) may be detected in a mixed manner, increasing measurement error.
When the solid concentration increases, the laser beam is attenuated by scattering, resulting in disadvantages such as the inability to detect velocity information.

加えて、（４）静電容量相関法の場合は、容量の変化が
極めて小さく、検出感度が低い。したがって、流路管径
が大きいときは測定できない。In addition, (4) in the case of the capacitance correlation method, the change in capacitance is extremely small and the detection sensitivity is low. Therefore, measurement cannot be performed when the diameter of the flow path pipe is large.

また、水との混相液では、水の誘電率は普通固体に比べ
て非常に大きいので測定できない。In addition, in a mixed phase liquid with water, the dielectric constant of water is usually much larger than that of a solid, so it cannot be measured.

さらに１検出信号のリード線の容量や浮遊容量が大きく
影響するので、測定誤差が大きくなるなどの種々の欠点
があシ、従来の測定法では、混相流中の固体速度の測定
は非常に困難で実用できるものでないと言える。Furthermore, since the capacitance and stray capacitance of the lead wires of the detection signal have a large influence, there are various drawbacks such as large measurement errors, and it is extremely difficult to measure solid velocity in multiphase flow using conventional measurement methods. It can be said that it is not something that can be put to practical use.

〔問題点を解決するための手段〕[Means for solving problems]

この発明は、上記問題点を解決するためになされたもの
で、固気および固液混相流の流路壁の上流側に設けられ
混相流と摩擦すると摩擦音を発生する上流側の接触板と
、この上流側の接触板が発生する摩擦音を検出して電気
信号に変換する上流側の圧電素子と、上流側の接触板と
所定の間隔をもって流路壁の下流側に設けられ混和流と
摩擦すると摩擦音を発生する下流側の接触板と、この下
流側の接触板が発生する摩擦音を検出して電気信号に変
換する下流側の圧電素子と、上流側と下流側の圧電素子
の出力の遅延時間に対する相関から流路内の固体分の流
速を求める信号処理器とを設けたものである。This invention was made to solve the above problems, and includes an upstream contact plate that is provided on the upstream side of the channel wall for solid-gas and solid-liquid multiphase flow and generates friction noise when it rubs against the multiphase flow. The upstream contact plate detects the generated frictional noise and converts it into an electrical signal.The upstream piezoelectric element detects the frictional noise generated and converts it into an electrical signal.The upstream contact plate is provided on the downstream side of the channel wall at a predetermined distance from the upstream contact plate, and is connected to a piezoelectric element that detects the friction noise generated and converts it into an electric signal. A downstream contact plate that generates friction noise, a downstream piezoelectric element that detects the friction noise generated by this downstream contact plate and converts it into an electrical signal, and a delay time between the outputs of the upstream and downstream piezoelectric elements. This system is equipped with a signal processor that determines the flow velocity of solids in the flow path from the correlation between the flow rate and the flow rate.

〔作用〕[Effect]

この発明は、固気および固液混相流の濃度と流速に比例
した摩擦音が所定間隔離れた上流側と下流側の接触板よ
シ発生し、この摩擦音を上流側と下流側の圧電素子で検
出して電気信号を発生させ、この両電気信号を信号処理
器に加えて両電気信号の遅延時間に対する相関から流路
内の固体分の流速が求まる。In this invention, frictional noise proportional to the concentration and flow velocity of solid-air and solid-liquid multiphase flows is generated by contact plates on the upstream and downstream sides separated by a predetermined interval, and this frictional noise is detected by piezoelectric elements on the upstream and downstream sides. An electric signal is generated, and both electric signals are applied to a signal processor, and the flow velocity of the solid in the flow path is determined from the correlation between the electric signals and the delay time.

〔実施例〕〔Example〕

以下、この発明の混相流中の固体速度測定装置の実施例
に−いて図面に基づき説明する。第１図はその一実施例
の構成を示すブロック図である。この第１図の実施例は
微粒炭焚ボイラを例にとって示すものであシ、図中の１
は固気および固液混相流の流路の一部断面図で、この流
路ｌの配管壁に貫通孔１１および２１が流体の流れ方向
にある距離をへだてて上流側と下流側にあけである。DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the solid velocity measuring device in a multiphase flow according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of one embodiment. The embodiment shown in Fig. 1 is shown by taking a granule coal-fired boiler as an example.
is a partial cross-sectional view of a flow path for solid-gas and solid-liquid multiphase flow, in which through holes 11 and 21 are formed on the upstream and downstream sides at a certain distance in the fluid flow direction in the piping wall of this flow path l. be.

貫通孔１１．２１にはそれぞれこの貫通孔１１゜２１を
閉塞するように接触板１２．２２が取シ付けられている
。接触板１２．２２は流路１に流れる混相流と摩擦する
と、摩擦音を発生゛するものである。摩擦音は圧電素子
１３．２３によシ検出するようにしている。Contact plates 12.22 are attached to each of the through holes 11.21 so as to close the through holes 11.21. When the contact plates 12 and 22 rub against the multiphase flow flowing in the flow path 1, they generate frictional noise. Frictional sounds are detected by piezoelectric elements 13 and 23.

圧電素子１３．２３はそれぞれ接触板１２゜２２に流路
１の管路外に貼シ付けられている。The piezoelectric elements 13, 23 are each pasted on the contact plate 12, 22 outside the channel 1.

圧電素子１３　ｚ　２Ｊは摩擦音を電気信号に変換する
ものであシ、この電気信−号、は電圧増幅器１４゜２４
で増幅された後、信号処理器３０に送出するようにして
いる。信号処理器３０は両電圧増幅器１４．２４の出力
から圧電素子１３．２３の出力の遅延時間に対する相関
から流路１内の固体分の流速を求めるものである。The piezoelectric element 13z2J converts frictional sound into an electric signal, and this electric signal is transmitted to the voltage amplifier 14゜24.
After being amplified, the signal is sent to the signal processor 30. The signal processor 30 determines the flow velocity of the solid component in the flow path 1 from the correlation between the outputs of the voltage amplifiers 14 and 14 and the delay time of the output of the piezoelectric element 13 and 23.

次に、以上のように構成されたこの発明の混相流中の固
体速度測定装置の作用について説明する。流路１内を微
粉炭が空気輸送されて流れて入るとき、流路１内の微粉
炭が本来もっている“ゆらぎ″現象、すなわち微粉炭の
わづかな濃度変化があシ第１図の２および３，４．５の
ように濃度分布がある。Next, the operation of the apparatus for measuring solid velocity in a multiphase flow according to the present invention configured as described above will be explained. When the pulverized coal is pneumatically transported and flows into the flow path 1, there is a "fluctuation" phenomenon that the pulverized coal in the flow path 1 originally has, that is, a slight change in the concentration of the pulverized coal. There is a concentration distribution as shown in 3 and 4.5.

濃度分布２はわづかであるが微粉炭の濃度が温いとき、
濃度分布３はそれよりもわづかに淡いときというように
不規則に分布して上流から下流に流れている。Concentration distribution 2 is slight, but when the concentration of pulverized coal is warm,
Concentration distribution 3 is irregularly distributed and flows from upstream to downstream, with the concentration being slightly lighter than that.

いま、時間１＝０において、濃度分布２および３の部分
が上流側の接触板１２を摩擦しながら流れるとき摩擦音
を発生し、それを圧電素子１３にて検知し、電圧増幅器
−１４ｔ−通シ、その出力は第２図（、）のごとくその
濃度および流速に比例して出力信号Ａとなる。Now, at time 1 = 0, when the parts of concentration distributions 2 and 3 flow while rubbing against the upstream contact plate 12, a frictional sound is generated, which is detected by the piezoelectric element 13 and is transmitted through the voltage amplifier 14t. , its output becomes an output signal A in proportion to its concentration and flow rate, as shown in FIG. 2(,).

一方Ｔｏｅ後には、濃度分布２，３は下流側の接触板２
３を摩擦しながら通過し、同様に圧電素子２４にて検知
され、ＷＪｚ図（ｂ）のごとく出力信号Ｂとなる。On the other hand, after Toe, the concentration distributions 2 and 3 are the same as those of the downstream contact plate 2.
3 while rubbing, and is similarly detected by the piezoelectric element 24, resulting in an output signal B as shown in the WJz diagram (b).

出力信号ＡおよびＢは信号処理器３０へ入力される。信
号処理器３０は上流側の出力信号Ａと下流側の出力信号
Ｂとの相関を求めるものである。すなわち出力信号Ａと
Ｂとの相関ψえ、Ｂは で表わされる。Output signals A and B are input to signal processor 30. The signal processor 30 determines the correlation between the upstream output signal A and the downstream output signal B. That is, the correlation ψ between the output signals A and B, B, is expressed by .

第３図は遅延時間に対して求めた相関曲線である。すな
わち第３図の曲線のビークつまシ相関が一番強い点は上
流側の出力信号Ａを７０秒遅らせて下流側の出力信号Ｂ
と全く同一にときであるからこのピーク点を求めること
によシ、τ＝ＴＯを求めることができる。これによシ管
内微粉炭の平均速度νは、 なお、この発明は、微粉炭焚ボイラ、ＣＯＭおよび圓焚
ボイラ、セメントプラント、穀物輸送管などの固気およ
び固液混相流中の固体分の速度測定などに応用できるも
のである。FIG. 3 is a correlation curve obtained with respect to delay time. In other words, the point on the curve in Figure 3 where the peak-to-peak correlation is strongest is when the upstream output signal A is delayed by 70 seconds and the downstream output signal B is detected.
By finding this peak point, it is possible to find τ=TO. Accordingly, the average velocity ν of pulverized coal in the pipe is This can be applied to speed measurements, etc.

〔発明の効果〕〔Effect of the invention〕

以上のように、この発明の混相流中の固体速度測定装置
によれば、固気および固液混相流中における微小な濃度
差を２点間に設置した接触板と摩擦させ、そのときの摩
擦音を圧電素子で検知して電気信号に変換し、この両電
気信号の遅延時間に対する相関から信号処理器で流速を
求めるようにしたので、流れ中の微粉炭の濃淡の微少変
動による摩擦音を高感度で検出でき、相関曲線のピーク
が明瞭に得られ、速度測定の精度が向上する。As described above, according to the device for measuring solid velocity in a multiphase flow of the present invention, minute concentration differences in solid-air and solid-liquid multiphase flows are caused to rub against the contact plate installed between two points, and the frictional noise generated at that time is is detected by a piezoelectric element and converted into an electrical signal, and the flow velocity is determined by a signal processor from the correlation between these two electrical signals with respect to the delay time.This enables high sensitivity to detect fricative noise caused by minute fluctuations in the density of pulverized coal in the flow. , the peak of the correlation curve can be clearly obtained, and the accuracy of speed measurement is improved.

【図面の簡単な説明】[Brief explanation of drawings]

第１図はこの発明の混相流中の固体速度測定装置の一実
施例の構成を示すブロック図、第２図（、）および第２
図（ｂ）はそれぞれ同上混相流中の固体速度測定装置に
おける電圧増幅器の出力信号を示す図、第３図は同上混
相流中の固体速度測定装置における信号処理器で得られ
る遅延時間に対する相関曲線を示す図である。 １・・・流路、２〜５・・・濃度分布、１２．２２・・
・接触板、１３．２３・・・圧電素子、３０・・・信号
処理器。 出願人復代理人　弁理士　鈴　江　武　彦第１図 第２図 □　ｔ □を 篤３図 −’ｃFigure 1 is a block diagram showing the configuration of an embodiment of the device for measuring solid velocity in multiphase flow according to the present invention, Figure 2 (, ), and Figure 2
Figure (b) is a diagram showing the output signal of the voltage amplifier in the solid-state velocity measuring device in multiphase flow as above, and Fig. 3 is a correlation curve for the delay time obtained by the signal processor in the solid-state velocity measuring device in multiphase flow as above. FIG. 1...Flow path, 2-5...Concentration distribution, 12.22...
・Contact plate, 13.23...Piezoelectric element, 30...Signal processor. Applicant's sub-agent Patent attorney Takehiko Suzue Figure 1 Figure 2 □ t □ Atsushi Figure 3-'c

Claims (1)

【特許請求の範囲】[Claims] 固気および固液混相流の流路壁の上流側に設けられ混相
流と摩擦すると摩擦音を発生する上流側の接触板と、こ
の上流側の接触板が発生する摩擦音を検出して電気信号
に変換する上流側の圧電素子と、上流側の接触板と所定
の間隔をもって流路壁の下流側に設けられ混相流と摩擦
すると摩擦音を発生する下流側の接触板と、この下流側
の接触板が発生する摩擦音を検出して電気信号に変換す
る下流側の圧電素子と、上流側と下流側の圧電素子の出
力の遅延時間に対する相関から流路内の固体分の流速を
求める信号処理器とよりなる混相流中の固体速度測定装
置。An upstream contact plate is installed on the upstream side of the channel wall for solid-gas and solid-liquid multiphase flow, and generates frictional noise when it rubs against the multiphase flow, and this upstream contact plate detects the generated frictional noise and converts it into an electrical signal. A piezoelectric element on the upstream side that converts, a contact plate on the downstream side that is provided at a predetermined distance from the upstream contact plate on the downstream side of the channel wall and generates frictional noise when it rubs against the multiphase flow, and this contact plate on the downstream side. A piezoelectric element on the downstream side that detects the friction noise generated and converts it into an electric signal, and a signal processor that calculates the flow velocity of solids in the flow path from the correlation between the output of the piezoelectric elements on the upstream and downstream sides with respect to the delay time. A device for measuring solid velocity in multiphase flow.